HOST-PATHOGEN-ENVIRONMENT INTERACTIONS: IMPACT ON ANIMAL HEALTH AND DISEASE IN VIRGINIA

Major Goals and Objectives: The complexity of global challenges related to emerging infectious disease and its relationship to food animal production, consumer health and natural environments requires a multi-prong approach in the understanding of host-pathogen-environment interactions.Objective 1: To employ sensitive cutting-edge technologies for efficiently diagnosing emerging, re-emerging and new infectious diseases that impair productivity of food animal populations and/or threaten public health.Rationale and Goal: When clinical signs are unclear or the infectious agent is not common (e.g. foreign animal disease), the traditional approach is to perform a large number of assays or perform serial testing for multiple pathogens until the causative agent is identified. This can be costly and time consuming which can be of particular concern in groups of animals or when export restrictions are affected. Current technology to sequence genetic material from samples including pathogenic organisms has advanced to the point that there is minimal startup cost and material costs are comparable to that of other testing approaches. Three factors allow this approach to now be viable. First, the cost of sequencing has dropped rapidly so that it is now possible to perform this at a cost comparable to that of traditional testing. Second, computational approaches have improved so that this can be done on a typical laptop computer. Third, technology has advanced so that this is approach can be performed using a USB connected sequencer and may soon be possible in the field. The goal is to utilize these and other cutting-edge technologies to efficiently and accurately detect infectious diseases, especially new diseases.Objective 2: To better understand the disease process (pathogenesis) affecting agricultural animals by using new approaches in order to develop effective vaccines, therapies, and delivery systems to counter pathogens.Rationale and Goal: For an ultimate goal of developing effective vaccines and targeted therapies, it is a pre-requisite to investigate how these infectious agents cause diseases. With the concern of emergence of new viruses (such as Usutu) present in wild birds and transmitted by mosquitoes, the specific goal will be to determine whether local birds and mosquitoes are susceptible to Usutu virus. This information will be critical for preparation in the event of Usutu virus introduction into Virginia or the US.Objective 3: To develop safer and effective alternatives to antibiotic and drug resistance.Rationale and Goal: Overuse and injudicious use of antibiotics have resulted in drug resistance, which is a serious concern. These antibiotics have also been found in livestock products, water-run offs, and sewage effluents, thereby human exposure is a public health concern. The overall goal is an urgent need to find better and safer alternatives to antibiotics.Objective 4: To develop novel alternatives to parasite-resistant commercial de-wormers and to select animals for enhanced genetically controlled resistance to parasites.Rationale and Goal: Resistance to de-wormers is a major concern in barber pole worm infestation in sheep and goats. This parasite feeds on blood and causes not only reduced growth and production, but also death in heavily infected animals. Lambs and kids are especially vulnerable because their immunity to the parasites has not yet developed. Parasites were not a major problem 25 years ago because there were several highly effective drugs available, but overuse has resulted in resistance. Currently, there are no new types of de-wormers that are likely to become available in the US in the near future and so the primary goal is the critical need for alternative methods of control for these parasites. The goal is to develop safer alternatives to tackle resistance to commercial de-wormers.Objective 5: To understand the effects of select agricultural chemicals (endocrine disrupters) in the environment on the immune system and microbiome.Rationale and Goal: Agricultural animals and farmers are exposed to pesticides and insecticides that are potentially endocrine disrupters that affect the health and productivity. Further, animals are fed hormones and antibiotics to promote faster growth. The groundwater and/or surface water can be contaminated with leaching of made manure lagoons, industrial farms that hold millions of gallons of liquid waste or through run-offs of crops sprayed with pesticides. These chemicals affect the productivity including milk production, are in residues in animal fat in food supply (thereby a health concern especially in susceptible subpopulations), and can modulate the immune system. Gut microbiome is now shown to be intricately involved in health and dysbiosis of microbiome is evident in many diseases32-33. Environmental chemicals can induce significant alterations in microbiome to affect the health and render vulnerable to diseases. The goal of this aim is to investigate the effects select endocrine disrupters on the immune system and microbiome.